The most common type of
cable from the Telephone Company Central Office to your home is 26 gauge cable.
In very old times it was open wire. That was gradually replaced with multi-pair
cables with paper insulation. Now the cable is plastic insulated.

All electrical cable has
certain characteristics. The most common are resistance and capacitance. There
is a very slight amount of inductance and insulation resistance between the two
conductors, for all practical purposes, with voice circuits, these two factors
can be ignored.

The simple explanation is
that one mile of cable from the telephone company to you home has about 430 Ohms
of resistance and .082 Microfarad of capacitance. If you wanted to build a mile
of cable you could coil up a mile of it and put it in a box. The simple way
would be to use four resistors (100 Ohms each) and a capacitor (.082 MFD 250 VDC
NP) to get an approximation.

With a bit of work you
can get this into a standard jack.:

The circuit is two way,
plug one end into the phone line and the other end to a telephone. See if a mile
of cable makes a difference. Or double or triple it for 2 or 3 miles of cable. I
used standard resistance values, so my one mile is really only 5000 feet.

If you want to be super
authentic, change one of the 100 ohm resistors to 120 ohms and add a 1 MH choke
in series with one of the resistors.

I have condensed a
complicated explanation to just one page. Refer to “Principles of Electricity
Applied to Telephone and Telegraph Work” by AT&T, available on E Bay for only a
few $$ in CD or a bit more in book form.

There is a loss in audio
associated with this circuit and it is about 3.5 DB at voice frequencies, and
more for higher frequencies.